The Commodore 1571 was arguably Commodore's finest 5¼" floppy disk drive, having the ability to use double-sided disks without the need to remove them and turn them over ("flippy disk") as in the previous Commodore drives on which it was based (Commodore 1541, 1570).
The 1571 was released to match the Commodore 128, both design-wise and feature-wise. The later C128D had a 1571 compatible drive integrated in the system unit. Permitting double the online capacity of the 1541, a disk formatted for/with the 1571 could hold 1328 256-byte blocks of data. A fundamental flaw, however, was the fact that the number of files on a disk was still limited to 144, like the 1541.
Like the single-sided 1570, the 1571 offered a data burst-mode when used with the C128, giving significantly better performance than the 1541. The 1571 could also closely emulate the 1541 for compatibility with copy-protected software titles. When used with a Commodore 64, the 1571 came up in 1541 compatibility mode by default and it was necessary to type a software command to switch the drive to double-sided 1571 mode.
The 1571 was noticeably quieter than its predecessor and tended to run cooler as well, even though, like the 1541, it had the power supply inside the unit (other contemporary Commodore drives, like the 1541-II and the 3½" 1581, came with external power supplies).
Unlike the 1541, which was limited to GCR formatting, the 1571 could do both GCR and MFM disk formats. A C128 in CP/M mode equipped with a 1571, was capable of reading and writing floppy disks formatted for many CP/M computers; specifically, the following formats:MS-DOS-formatted floppies as well. Numerous commercial and public-domain programs for this purpose became available, the best known being SOGWAP's "Big Blue Reader".